i found a scratch on my car and the fenderboard half-way falling, when i drove it back home tonight.

i am pretty sure it was not there this morning when i left home, and i didn't hit/wasn't hit by anybody today when drving it. so i guess it happened when the car was parked, but i don't know where it happened because i parked car at many different places during the whole day.

so, other than spending some time and money to repair it, is there anything i can do? will my car insurance cover something? i think there is an item called parking damage in my insurance, but i don't know how exactly it works, because i certainly have no evidence to show that the damage is not my own fault.

any tips would be really appreciated.
thank you very much.